I recently recieved a featherweight from a friend. It stitched well for about one row and then locked up. Is it ok to remove the screw at the left of the bobbin case to determine whether there is a thread caught in there???? I think the thread may be the cause of the stoppage.

turn the machine over. take off large "screw", lay bottom
plate aside. now you can look into the bobbin area & use
tweezers to get thread pieces. but first, take the throat plate off & check for thread pieces. IMPORTANT--read your
manual on how to put the throat plate back on---or you will
have another problem. when sewing, always a good idea to hold the threads at the back as you start to sew. and don't
turn the handwheel towards you.